If both Tx and Receiver gets charged over night which battery will expire first the TX or receiver in say 3 flights a day. I have a new Futaba 4EX TX and R168DF Receiver both have 600 mAh batteries. It seems to me the receiver would discharge first due to the current draw from movement of the servos and if that is the case wouldn't it be wise to invest in a larger capicity battery for the receiver? This is my first post, I really enjoy the site and I am looking forward to my first flight. Oh yes! I have them installed in a Tower Trainer 60 MK11.

Actually, they will both expire at about the same time if they are the same capacity. I haven't used that small of a battery in my tx in years, so I really can't remember exactly. All I remember is that after 3 or 4 flights max, I had both rx and tx on the quick field charger. Transmitting the rf signal requires about as much energy as four servos in a typical trainer setup. You might find that the rx runs down a little quicker--it all depends upon your style of flying. Style of flying affects rx battery time, but not tx battery time.

do yourself a favoir and get a voltomiter a loaded one ment for rc yes the rx back will drain first but who knows hwo many flights maybe you didnt get a full charge? its just too risky invest the 30$ and youl have it forever...(i use mine before EVER flight to see if the batteries are above 4.8 volts)

Welcome to RCU.
A voltmeter as suggested , is the for sure way to go and is only the for sure way of knowing.
Drain on your RX battery will depend on your flying style , if you putts around doing lazy 8`s , ect , your flight time will be extended. But if your thumbs ache after 15 mins. on the sticks , you might want to check your battery.

My transmitter battery always last for well over an hour and I attempt to size the receiver batteries to outlast the transmitter. The transmitter has a built in voltmeter, which I consider mandatory.

Bill

Tx voltmeter are good on digitail tx,s if your using one with the 3 lights use the voltometer it only taks 10 second longer the standered rc one does both and when you buy the wire for the rx the tx wire is in the same pack so unless you ahve a digital desplay i would also check the tx..

I want to thank everyone that responded to my question, I'll buy a voltmeter and do some checking....Regards, ron

Yeah, get a volt meter you can mount inside your plane (or outside, if you don't mind the look). That wil tell you how much you have left on your Rx battery. Your transmitter will take care of itself w/ it's volt meter. Don't fly when your Tx has less than 9v (I don't fly when it's under 9.5).

-Erik